volume | PIER Journals

Abstract

The conventional optimization of permanent magnet synchronous motors (PMSMs) for hybrid electric vehicles (HEVs) often neglects the dynamic nature of real-world driving cycles, resulting in suboptimal overall energy efficiency. To address this issue, this study proposes a multi-region efficiency optimization strategy that fully integrates actual driving cycles. First, motor operating points were extracted from the WLTC and CLTC standard driving cycles and identified as key operating regions via cluster analysis. A variance-based sensitivity analysis is then employed to quantify the contribution of each rotor parameter, thereby reducing the optimization dimension. The NSGA-III algorithm, coupled with finite element analysis (FEA), performs multi-objective optimization, targeting average efficiency and permanent magnet cost. A new method that comprehensively considers the average efficiency of both the cluster centers and boundaries of the operating points was proposed as an optimization objective. The results show that the optimal candidate improves the average efficiency to 96.77\%. Depending on the practical requirements, different candidate points are ultimately selected by balancing efficiency, cost, and driving comfort.

1. Chiver, Olivian, Ioan Radu Sugar, and Liviu Neamt, "Study on the selection of electric motor/engine on the performance of hybrid vehicles," Energies, Vol. 17, No. 14, 3529, 2024.
doi:10.3390/en17143529 Google Scholar

2. Liu, Ye, Ziqiang Wei, Kang Ma, and Zhuoran Zhang, "Improved thermal management and analysis for high-power heat pipe cooled FSCW PMSM for HEV auxiliary power unit application," IEEE Transactions on Energy Conversion, Vol. 39, No. 2, 1154-1167, 2024.
doi:10.1109/tec.2023.3339678 Google Scholar

3. Eduku, Stephen, Joseph Sekyi-Ansah, Mohammed Okoe Alhassan, and Ebenezer Narh Odonkor, "Design optimization and comparative performance analysis of a novel five-phase fault-tolerant spoke-type flux-switching permanent magnet motor for EV/HEV applications," Journal of Electrical Engineering & Technology, Vol. 20, No. 3, 1541-1556, 2025.
doi:10.1007/s42835-024-02081-6 Google Scholar

4. El Hajji, Taha, Sami Hlioui, François Louf, Mohamed Gabsi, Guillaume Mermaz-Rollet, and M’Hamed Belhadi, "Optimal design of high-speed electric machines for electric vehicles: A case study of 100 kW V-shaped interior PMSM," Machines, Vol. 11, No. 1, 57, 2023.
doi:10.3390/machines11010057 Google Scholar

5. Liu, Feng, Xiuhe Wang, and Hongye Wei, "Electromagnetic performance analysis, prediction, and multiobjective optimization for U-type IPMSM," IEEE Transactions on Industrial Electronics, Vol. 71, No. 9, 10322-10334, 2024.
doi:10.1109/tie.2023.3342326 Google Scholar

6. Meddour, Aissam Riad, Nassim Rizoug, Patrick Leserf, Christopher Vagg, Richard Burke, and Cherif Larouci, "Optimization of the lifetime and cost of a PMSM in an electric vehicle drive train," Energies, Vol. 16, No. 13, 5200, 2023.
doi:10.3390/en16135200 Google Scholar

7. Yuan, Bin, Hui Li, Xuewei Xiang, and Hao Zhou, "Energy efficiency optimization design for cycle position servo PMSM based on operating energy consumption model," IEEE Open Journal of the Industrial Electronics Society, Vol. 6, 591-602, 2025.
doi:10.1109/ojies.2025.3555606 Google Scholar

8. Kolsi, H., N. Ben Hadj, M. Chaieb, and R. Neji, "Design of permanent magnet synchronous motor by means of power density optimization for e-vehicle applications," International Review on Modelling & Simulations, Vol. 15, No. 3, 203, 2022.
doi:10.15866/iremos.v15i3.21739 Google Scholar

9. Zhu, Xiaoyong, Min Jiang, Zixuan Xiang, Lei Xu, Yunyun Chen, and Li Quan, "Design and optimization of a multi-region high-efficiency permanent magnet motor with enhanced energy efficiency," IEEE Transactions on Energy Conversion, Vol. 40, No. 3, 2169-2178, 2025.
doi:10.1109/tec.2025.3545594 Google Scholar

10. Wang, Biao, Guangwei Liu, Zhenyao Xu, and Fengge Zhang, "Cost optimization method for less-rare-earth permanent magnet synchronous motor based on surrogate model," 2024 27th International Conference on Electrical Machines and Systems (ICEMS), 1808-1813, Fukuoka, Japan, 2024.
doi:10.23919/ICEMS60997.2024.10921112

11. Sun, Xiaodong, Ziyin Dong, Zhijia Jin, Gang Lei, and Xiang Tian, "System-level energy management optimization of power-split hybrid electric vehicle based on nested design," IEEE Transactions on Industrial Electronics, Vol. 71, No. 9, 10987-10997, 2024.
doi:10.1109/tie.2023.3340212 Google Scholar

12. Sardar, Muhammad Usman, Dou Manfeng, Umar Saleem, Mannan Hassan, and Muhammad Kashif Nawaz, "State-of-the-art design optimization of an IPM synchronous motor for electric vehicle applications," 2022 International Conference on Emerging Trends in Electrical, Control, and Telecommunication Engineering (ETECTE), 1-6, Lahore, Pakistan, 2022.
doi:10.1109/ETECTE55893.2022.10007182

13. Mohammadi, Hossain, Sandeep Saini, Reza Nasirizarandi, and Aiswarya Balamurali, Drive cycle-based design optimization of traction motor drives for battery electric vehicles using data-driven approaches, 2024.
doi:10.4271/2024-01-2172

14. Lee, Gi-haeng and Yong-min You, "Efficiency optimization of the main operating points of an ev traction motor," Applied Sciences, Vol. 15, No. 1, 368, 2025.
doi:10.3390/app15010368 Google Scholar

15. Mahmouditabar, Farshid, Ehsan Farmahini Farahani, Volker Pickert, and Mehmet C. Kulan, "Multi-physics LCA-based design optimization of an interior permanent magnet motor for EVs," Energies, Vol. 18, No. 23, 6167, 2025.
doi:10.3390/en18236167 Google Scholar

16. Zhang, Yiming, Liangyu Fei, Chee-Kong Chui, Chin-Boon Chng, Shengdun Zhao, and Jingxiang Li, "Machine learning surrogate model optimized by improved sparrow search algorithm for multi-objective optimization of permanent magnet synchronous motor direct-drive pump," IEEE Transactions on Vehicular Technology, Vol. 73, No. 9, 12773-12786, 2024.
doi:10.1109/tvt.2024.3395535 Google Scholar

17. Zhu, Zhihao, Xiang Li, Yingzhi Lin, Hao Wu, Junhui Chen, Niannian Zhang, Thomas Wu, Bo Lin, and Suyan Wang, "Multi-objective optimization design of high-power permanent magnet synchronous motor based on surrogate model," Sustainability, Vol. 18, No. 3, 1705, 2026.
doi:10.3390/su18031705 Google Scholar

18. Liu, Lin, Youguang Guo, Wenliang Yin, Gang Lei, Xiaodong Sun, and Jianguo Zhu, "Efficient design optimization of PMSM drive systems using improved equivalent-circuit-based loss minimization control," IEEE Transactions on Industrial Electronics, Vol. 72, No. 4, 3280-3291, 2025.
doi:10.1109/tie.2024.3447748 Google Scholar

19. Xu, Naixi, Xiaodong Sun, and Christopher H. T. Lee, "Hierarchical multiobjective optimization of spoke-type axial-flux pmsms using transfer learning and improved grey wolf algorithm," IEEE Transactions on Industrial Electronics, Vol. 73, No. 5, 6780-6791, 2026.
doi:10.1109/tie.2025.3642439 Google Scholar

20. Braband, Matthias, Matthias Scherer, and Holger Voos, "Global sensitivity analysis of economic model predictive longitudinal motion control of a battery electric vehicle," Electronics, Vol. 11, No. 10, 1574, 2022.
doi:10.3390/electronics11101574 Google Scholar

21. Jiang, Xuefeng, Jichen Niu, Jing Xu, Tingyuan Zhang, Wangyang Zhou, Qingmin Jiang, Jiahui Xu, and Kai Ma, "Design and optimization of a lightweight five-phase permanent magnet fault-tolerant motor based on improved NSGA-III," IEEE Transactions on Transportation Electrification, Vol. 12, No. 2, 2899-2909, 2026.
doi:10.1109/tte.2025.3646328 Google Scholar

22. Hernandez, C., J. Lara, M. A. Arjona, F. J. Martinez, J. E. Moron, R. Escarela-Perez, and J. Sykulski, "Electromagnetic optimal design of a PMSG considering three objectives and using NSGA-III," IEEE Transactions on Magnetics, Vol. 58, No. 9, 1-4, 2022.
doi:10.1109/tmag.2022.3167306 Google Scholar

Dr. Zhijia Jin

Dr. Xinyu Gao

Dr. Guanghua Li

Dr. Kaikai Diao